Dr Kirkby,
Quite true, of course.? I was aiming to verify that the cal kit constants assumed "near perfect" standards.? If the cal kit assumes offset short and open then measuring a non-offset short or open will not appear as a small point at the left or right of the Smith chart.
--John Gord
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On Fri, Oct 25, 2024 at 03:28 PM, Dr. David Kirkby, Kirkby Microwave Ltd wrote:
The 8753D 7mm cal kit setting assumes nearly perfect standards.? As I remember, only the open has any corrections, and that is something like 90fF of fringing capacitance.?
If you select the 7mm kit and then calibrate at the solder end of your pigtails with a 50ohm SMD resistor, a "short" short and a "short" open, you should get decent results.? Verify by measuring your short, open, and load after calibration to see if you get the results you expect.? Try to keep the leads at the end of your pigtail very short.
--John Gord
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Measuring the standards use to perform a calibration will not provide any verification. If a 10 ohm resistor was used during calibration, it will read 50 ohms on the VNA.?
